Development of efficient photocatalysts is essential for carbon dioxide (CO₂) photocatalytic reduction. In this study, Z-scheme CoAl-layered double hydroxide (LDH)/indium vanadate (InVO₄) heterojunction photocatalysts were synthesized using hydrothermal method, and their performance toward CO₂ reduction and mechanism were determined. Results of characterizations showed that the CoAl-LDH/InVO₄-30 exhibited desired morphology, the most efficient photogenerated carriers separation and charge transfer, and the highest photocurrent response. X-ray photoelectron spectroscopy (XPS) and electron spin resonance (ESR) manifested that charge transfer of the CoAl-LDH/InVO₄ conformed to Z-scheme mechanism. The CoAl-LDH/InVO₄-30 exhibited the highest carbon monoxide (CO) yield of 174.4 μmol g⁻¹ within 2 h of reaction, which was 2.46 and 9.79 times of pure CoAl-LDH and InVO₄, respectively. The CO selectivity was up to nearly 100%. Moreover, in-situ fourier transform infrared spectroscopy (ISFT-IR) demonstrated that bicarbonate (HCO₃*) and carboxylate (COOH*) were the main intermediates during the CO₂ reduction process, and possible CO₂ reduction pathways were proposed. This work provides a reference for construction of Z-scheme LDH-based heterojunctions for efficient CO₂ photoreduction.

开发高效的光催化剂对于二氧化碳（CO ₂）光催化还原至关重要。本研究采用水热法合成了Z型CoAl层状双氢氧化物（LDH）/钒酸铟（InVO _{4 ）异质结光催化剂，并确定了它们对CO 2}的还原性能和机理。表征结果表明，CoAl-LDH/InVO ₄ -30 表现出理想的形貌，最有效的光生载流子分离和电荷转移，以及最高的光电流响应。X 射线光电子能谱 (XPS) 和电子自旋共振 (ESR) 表明 CoAl-LDH/InVO _{4的电荷转移}符合Z-方案机制。CoAl-LDH/InVO ₄ -30在反应2 h内的一氧化碳(CO)产率最高，为174.4 μmol g ^-1，分别是纯CoAl-LDH和InVO ₄的2.46倍和9.79倍。CO 选择性高达近 100%。此外，原位傅里叶变换红外光谱（ISFT-IR）表明碳酸氢盐（HCO _{3 *）和羧酸盐（COOH*）是CO 2}还原过程的主要中间体，并提出了可能的CO ₂还原途径。该工作为构建Z型LDH基异质结以实现高效的CO ₂光还原提供了参考。